Pressure Regulating (Anti-G) Valves

4. Provide the pilot with a physical indication of the approximate acceleration to which the air- craft is being subjected Typical Anti-G System Most anti-g systems are similar to the one illustrated in figure 1-2. This system consists of a supply line, an air filter, a pressure regulating valve, a connecting hose, and a suit attachment fitting (single quick disconnect or composite quick disconnect). The air pressure used in this system may be taken directly from the engine compressor bleed-air ducting, but is usually taken off the air-conditioning ducting downstream from the heat exchanger. Pressure Regulating (Anti-G) Valves There are two types of anti-g valves used on the various naval aircraft. One type has a dual pressure range (HI or LO) that maybe controlled by the pilot. The other type has a fixed pressure output that corresponds roughly to the high (HI) pressure output of the dual pressure valve. Both valves perform the dual functions of regulating the air pressure received from the aircraft’s bleed- air system and metering this pressure in varying amounts proportional to the g forces exerted upon the aircraft and its occupants. Newer aircraft are designed with an anti-g system that has a single-stage pressure regulating valve (fig. 1-3). This valve begins to open at approximately 1.5 g’s, and pressure is supplied to the suit at the rate of 1.5 psi for each additional g. The valve is designed to receive air pressure from the bleed-air system at varying pressures and to meter a maximum of 10 psi to the anti-g suit. A relief valve bleeds off the excess air pressure Figure 1-3.—Anti-g pressure regulating valve (single stage) Figure 1-2.—Anti-g system. 1-3